Progressive power ophthalmic lens
US5691798A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 27, 1995 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | Jul 27, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C2202/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A progressive power ophthalmic lens having a spherical distance viewing area, a progressive power portion with a decreasing radius of curvature along an umbilic meridian, and a spherical near viewing area. Power distribution functions are optimized for smooth transition along the principal directions of gaze. A statistically smoothed polynomial function of the general form Pm=b.sub.1 +b.sub.2 X+b.sub.3 X.sup.2 +. . . +b.sub.9 X.sup.8 defines the mean power at any point on the lens surface to regulate curvature variation. Thereby providing continuity of the visual field at the boundaries of the principal lens zones and creating an integrated visual field as the eye traverses the lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.